/*
 * This file is part of the OpenSCADA project
 * Copyright (C) 2006-2010 TH4 SYSTEMS GmbH (http://th4-systems.com)
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 */

package org.openscada.opc.lib.list;

import java.net.UnknownHostException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

import org.jinterop.dcom.common.JIException;
import org.jinterop.dcom.core.JIClsid;
import org.jinterop.dcom.core.JIComServer;
import org.jinterop.dcom.core.JISession;
import org.openscada.opc.dcom.list.ClassDetails;
import org.openscada.opc.dcom.list.Constants;
import org.openscada.opc.dcom.list.impl.OPCServerList;

import rpc.core.UUID;

/**
 * A wrapper around the {@link OPCServerList} class which makes the handling somewhat easier.
 * @author Jens Reimann &lt;jens.reimann@th4-systems.com&gt;
 * @since 0.1.8
 *
 */
public class ServerList
{
    private final JISession _session;

    private final OPCServerList _serverList;

    /**
     * Create a new instance with an already existing session
     * @param session the DCOM session
     * @param host the host to query
     * @throws IllegalArgumentException
     * @throws UnknownHostException
     * @throws JIException
     */
    public ServerList ( final JISession session, final String host ) throws IllegalArgumentException, UnknownHostException, JIException
    {
        this._session = session;
        JIComServer comServer = new JIComServer ( JIClsid.valueOf ( Constants.OPCServerList_CLSID ), host, this._session );
        this._serverList = new OPCServerList ( comServer.createInstance () );
    }

    /**
     * Create a new instance and a new DCOM session
     * @param host the host to contact
     * @param user the user to use for authentication
     * @param password the password to use for authentication
     * @throws IllegalArgumentException
     * @throws UnknownHostException
     * @throws JIException
     */
    public ServerList ( final String host, final String user, final String password ) throws IllegalArgumentException, UnknownHostException, JIException
    {
        this ( host, user, password, null );
    }

    /**
     * Create a new instance and a new DCOM session
     * @param host the host to contact
     * @param user the user to use for authentication
     * @param password the password to use for authentication
     * @param domain The domain to use for authentication
     * @throws IllegalArgumentException
     * @throws UnknownHostException
     * @throws JIException
     */
    public ServerList ( final String host, final String user, final String password, final String domain ) throws IllegalArgumentException, UnknownHostException, JIException
    {
        this ( JISession.createSession ( domain, user, password ), host );
    }

    /**
     * Get the details of a opc class
     * @param clsId the class to request details for
     * @return The class details
     * @throws JIException
     */
    public ClassDetails getDetails ( final String clsId ) throws JIException
    {
        return this._serverList.getClassDetails ( JIClsid.valueOf ( clsId ) );
    }

    /**
     * Fetch the class id of a prog id
     * @param progId The prog id to look up
     * @return the class id or <code>null</code> if none could be found.
     * @throws JIException
     */
    public String getClsIdFromProgId ( final String progId ) throws JIException
    {
        JIClsid cls = this._serverList.getCLSIDFromProgID ( progId );
        if ( cls == null )
        {
            return null;
        }
        return cls.getCLSID ();
    }

    /**
     * List all servers that match the requirements
     * @param implemented All implemented categories
     * @param required All required categories
     * @return A collection of "class ids"
     * @throws IllegalArgumentException
     * @throws UnknownHostException
     * @throws JIException
     */
    public Collection<String> listServers ( final Category[] implemented, final Category[] required ) throws IllegalArgumentException, UnknownHostException, JIException
    {
        // convert the type safe categories to plain UUIDs
        UUID[] u1 = new UUID[implemented.length];
        UUID[] u2 = new UUID[required.length];

        for ( int i = 0; i < implemented.length; i++ )
        {
            u1[i] = new UUID ( implemented[i].toString () );
        }

        for ( int i = 0; i < required.length; i++ )
        {
            u2[i] = new UUID ( required[i].toString () );
        }

        // get them as UUIDs
        Collection<UUID> resultU = this._serverList.enumClassesOfCategories ( u1, u2 ).asCollection ();

        // and convert to easier usable strings
        Collection<String> result = new ArrayList<String> ( resultU.size () );
        for ( UUID uuid : resultU )
        {
            result.add ( uuid.toString () );
        }
        return result;
    }

    /**
     * List all servers that match the requirements and return the class details
     * @param implemented All implemented categories
     * @param required All required categories
     * @return a collection of matching server and their class information
     * @throws IllegalArgumentException
     * @throws UnknownHostException
     * @throws JIException
     */
    public Collection<ClassDetails> listServersWithDetails ( final Category[] implemented, final Category[] required ) throws IllegalArgumentException, UnknownHostException, JIException
    {
        Collection<String> resultString = listServers ( implemented, required );

        List<ClassDetails> result = new ArrayList<ClassDetails> ( resultString.size () );

        for ( String clsId : resultString )
        {
            result.add ( getDetails ( clsId ) );
        }

        return result;
    }
}
